• Title/Summary/Keyword: repeated dose

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Leucostim, A Human Granulocyte-Colony Stimulating Factor, Facilitates Granulopoiesis After Bone Marrow Transplantation In Mice

  • Ahn, Byoung-Ok;Kang, Soo-Hyoung;Kim, Won-Bae
    • Biomolecules & Therapeutics
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    • v.8 no.3
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    • pp.213-216
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    • 2000
  • In vivo administration of Leucostim, a human recombinant granulocyte colony-stimulating factor (G-CSF), was evaluated for the effects on survival, hematologic recovery, and colony forming unit- spleen (CFU-5) in murine bone marrow transplantation (BMT) model. Sublethally irradiated (9 Gy) mice received bone marrow cells from untreated mice, and then were treated with G-CSF subcutaneously at doses of 2.5,5, or $10\mu\textrm{g}$/kg or vehicle solution (control) for 14 days from one day after BMT. There was no effect of irradiation and BMT on mortality. The repeated subcutaneous injections of Leucostim for 14 days post- BMT significantly facilitated hematologic recovery compared with vehicle control in a dose-dependent manner. Moreover, mice treated with Leucostim had significantly increased numbers of CFU-s colonies on day 10 post-BMT. These results suggest that Leucostim, a new G-CSF, has beneficial effects on hematologic reconstitution after BMT.

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Effects of Lignans on Hepatic Drug-Methabolizing Enzymes

  • Shin, Kuk-Hyun;Woo, Won-Sick;Lee, Jung-Yun;Han, Yong-Bong
    • Archives of Pharmacal Research
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    • v.13 no.3
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    • pp.265-268
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    • 1990
  • The effects of lignans, related to macelignan, on hepatic microsomal drug-metabolizing enzyme (DME) activity were evaluated to elucidate the structure-activity relationship in mice and rats. The compounds carrying the methylenedioxyphenyl nucleus were found to be the msot potent among compounds tested; which not only produced a marked inhibition of DME with a single dose but a significant induction with repeated treatments. Lack of the methylenedioxy group caused marked decrease in the activity, implying that a methylenedioxy group is essential and of major importance eliciting DME modifying activity.

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Determination and classification of intraoral phosphor storage plate artifacts and errors

  • Deniz, Yesim;Kaya, Seher
    • Imaging Science in Dentistry
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    • v.49 no.3
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    • pp.219-228
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    • 2019
  • Purpose: The aim of this study was to determine the reasons and solutions for intraoral phosphor storage plate (PSP) image artifacts and errors, and to develop an appropriate classification of the artifacts. Materials and Methods: This study involved the retrospective examination of 5,000 intraoral images that had been obtained using a phosphor plate system. Image artifacts were examined on the radiographs and classified according to possible causative factors. Results: Artifacts were observed in 1,822 of the 5,000 images. After examination of the images, the errors were divided into 6 groups based on their causes, as follows: images with operator errors, superposition of undesirable structures, ambient light errors, plate artifacts (physical deformations and contamination), scanner artifacts, and software artifacts. The groups were then re-examined and divided into 45 subheadings. Conclusion: Identification of image artifacts can help to improve the quality of the radiographic image and control the radiation dose. Knowledge of the basic physics and technology of PSP systems could aid to reduce the need for repeated radiography.

Study on Single-dose Intramuscular Toxicity of Shinbaro Pharmacopuncture in Sprague-Dawley (SD) Rats and Beagle Dogs (신바로 약침의 SD 랫드와 비글견에 대한 단회 근육투여 독성시험)

  • Lee, Jin-Ho;Chung, Hwa-Jin;Lee, In-Hee;Lee, Jae-Woong;Kim, Eun-Jee;Kim, Min-Jeong
    • Journal of Korean Medicine Rehabilitation
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    • v.25 no.3
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    • pp.1-9
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    • 2015
  • Objectives To evaluate Shinbaro Pharmacopuncture safety through analysis of potential single-dose intramuscular toxicity of Sinbaro Pharmacopucture in SD rats and Beagle dogs. Methods Single-dose intramuscular toxicity of Shinbaro Pharmacopuncture was assessed in accordance with Korea Food and Drug Administration Guidelines for toxicity testing of Medicinal Products. The SD rats were treated intramuscularly with Shinbaro Pharmacopuncture at doses of 0, 4.6, 9.2, and 18.5 mg/kg, respectively. The Beagle dogs were treated intramuscularly with Shinbaro Pharmacopuncture at doses of 2.3, and 4.6 mg/kg, respectively, and after 3 days, the procedure was repeated a second time at doses of 0.6, and 1.2 mg/kg, respectively, for toxicity testing. Mortality, change in body weight, and necropsy findings were examined for the study period. Results There were no mortalities, general symptoms, or body weight changes in the SD rats. While pyelectasis of the left kidney was observed in a male rat in the 4.6 mg/kg administration group, natural occurrence is common, and does not appear to be related with the test substance. No mortalities were observed in the Beagle dogs. In assessment of general symptoms, a female dog in the 9.2 mg/kg group displayed body weight decrease due to leftover food, but the change in body weight was within the normal range seen at 6~7 months, and the necropsy findings were not significant. The toxicity of the test substance appears to be minimal. Conclusions The results suggest that the lethal dose 50 ($LD_{50}$) and approximate lethaldose (ALD) value in single intramuscular administration of Shinbaro Pharmacopuncture in SD rats and Beagle dogs are higher than 18.5 mg/kg.

Placenta Transfer and Toxicokinetics of Valproic Acid in Pregnant Cynomolgus Monkeys

  • Jeong, Eun-Ju;Yu, Wook-Joon;Kim, Choong-Yong;Chung, Moon-Koo
    • Toxicological Research
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    • v.26 no.4
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    • pp.275-283
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    • 2010
  • Placenta transfer study in non-human primate (NHP) is one of the crucial components in the assessment of developmental toxicity because of the similarity between NHP and humans. To establish the method to determine placenta transfer in non-human primate, toxicokinetics of valproic acid (VPA), a drug used to treat epilepsy in pregnant women, were determined in pregnant cynomolgus monkeys. After mating, pregnancy-proven females were daily administered with VPA at dose levels of 0, 20, 60 and 180 mg/kg by oral route during the organogenesis period from gestation day (GD) 20 to 50. Concentrations of VPA and its metabolite, 4-ene-VPA, in maternal plasma on GDs 20 and 50, and concentrations of VPA and 4-ene-VPA in placenta, amniotic fluid and fetus on GD 50 were analyzed using LC/MS/MS. Following single oral administration of VPA to pregnant monkeys, concentrations of VPA and 4-ene-VPA were generally quantifiable in the plasma from all treatment groups up to 4-24 hours post-dose, demonstrating that VPA was absorbed and the monkeys were systemically exposed to VPA and 4-ene-VPA. After repeated administration of VPA to the monkeys, VPA was detected in amniotic fluid, placenta and fetus from all treatment groups, demonstrating that VPA was transferred via placenta and the fetus was exposed to VPA, and the exposures were increased with increasing dose. Concentrations of 4-ene-VPA in amniotic fluid and fetus were below the limit of quantification, but small amount of 4-ene-VPA was detected in placenta. In conclusion, pregnant monkeys were exposed to VPA and 4-ene-VPA after oral administration of VPA at dose levels of 20, 60 and 180 mg/kg during the organogenesis period. VPA was transferred via placenta and the fetus was exposed to VPA with dose-dependent exposure. The metabolite, 4-ene VPA, was not detected in both amniotic fluid and fetus, but small amount of 4-ene-VPA was detected in placenta. These results demonstrated that proper procedures to investigate placenta transfer in NHP, such as mating and diagnosis of pregnancy via examining gestational sac with ultrasonography, collection of amniotic fluid, placenta and fetus after Caesarean section followed by adequate bioanalysis and toxicokinetic analysis, were established in this study using cynomolugus monkeys.

Renal Toxicity of High-dose Intravenous Immunoglobulin in Children with Kawasaki Disease and Idiopathic Thrombocytopenic Purpura (가와사끼병과 특발성 혈소판 감소성 자반증 환아에서 고용량 정주용 면역글로불린의 신독성 유무)

  • Jung Ji Ah;Kim Hye Soon;Seo Jeong Wan;Lee Seung Joo
    • Childhood Kidney Diseases
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    • v.2 no.2
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    • pp.133-137
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    • 1998
  • Purpose : To investigate renal toxicity of high-dose intravenous immunoglobulin(IVIG) in children with Kawasaki disease and idiopathic thrombocytopenic purpura. Methods : 23 children with Kawasaki disease and 7 children with idiopathic thrombocytopenic purpura who were treated with high-dose IVIG(2 g/kg) were evaluated for the change of urine output, blood urea nitrogen(BUN), serum creatinine(Scr), creatinine clearance(Ccr), tubular reabsorption of phosphorus(TRP), fractional excretion of sodium(FENa), 24hour urine ${\beta}_2$-microglobulin/creatinine(${\beta}_{2}MG/cr$) ratio and urine microalbumin/creatinine(MA/cr) ratio at post-IVIG 1 and 3 day. Results : There was no significant change of urine output, BUN, Scr, Ccr, TRP, 24hour urine ${\beta}_{2}MG/cr$ and MA/cr ratio after high-dose IVIG treatment. Transient increase of FENa at post-IVIG 1 day was the only significant change. Conclusion : There was no significant renal toxicity of high-dose IVIG in children with Kawasaki disease and idiopathic thrombocytopenic purpura who had normal renal function.

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Impedance Changes of Living Tissue During Radiation Exposure Dose (방사선 피폭선량에 대한 생체 조직의 임피던스 변화)

  • Kil, Sang Hyeong;Lee, Moo Seok;Nam, Ji Ho;Lee, Yeong Hwa;Kim, Gun Do;Lee, Jong Kyu
    • Journal of Radiation Protection and Research
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    • v.38 no.4
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    • pp.202-207
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    • 2013
  • Bioimpedance involves a lot of information related to living tissue. If there is alteration in bio tissue, its electrical characteristics also change. It is to study electrical characteristics of pork tenderlion in using a HP-4194A Impedance/Gain-phase analyzer instrument and electrical characteristics changes by graded radiation exposure dose. The results were as follow 1. Electrical characteristics of pork tenderlion in repeated measurement had high precision within ${\pm}5$% of coefficiency of variability. 2. During the measurement impedance absolute value and phase alteration did not show statistically significant difference.(p>0.05) 3. While impedance phase of electrical characteristics associated with frequency change was almost stable, impedance absolute value was in inverse proportion to frequency that means high inverse correlation of -0.096(r). 4. Impedance absolute value dropped in radiation exposure dose. The alteration of the value did not show statistically significant difference in 1 Gy, 2 Gy and 4 Gy.(p>0.05) However in radiation exposure dose of 10 Gy, the decrease of impedance absolute value was significantly different.(p<0.05) 5. Impedance phase according to radiation exposure dose change did not show statistically significant difference in 1 Gy, 2 Gy, 4 Gy, and 10 Gy(p>0.05).

Reduction of Radiation Exposure Dose of Eyeball and Thyroid for Chest and Abdomen CT Scan (흉부 및 복부 CT 검사 시 안구와 갑상선의 방사선 피폭선량 저감)

  • Lee, Jun Seok;Chon, Kwon Su
    • Journal of the Korean Society of Radiology
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    • v.13 no.2
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    • pp.147-151
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    • 2019
  • In chest and abdomen CT scans, the radiation exposure doses by scattering lines were measured at the eyeball and thyroid. Radiation exposure was investigated by using shielding devices. The chest and abdomen CT scan protocols used in the real examination were applied to measure and compare radiation doses before and after the use of shielding devices at the eyeball and the thyroid. The radiaton doses were measured with OSLD dosimeters. Barium, tungsten sheets, goggles and neck shields were used to protect the scattered X-ray. The chest CT scans showed respectively 3.01 mSv and 6.21 mSv at the eyeball and the thyroid by the scattered X-ray. The abdomen CT scans showed 0.55 mSv and 3.22 mSv for the eyeball and the thyroid respectively. Barium and tungsten sheets had 11% to 13% protection rates at the eyeball and the thyroid for chest CT scan, and 34% to 49% reduction in radiation dose for the abdomen CT scan. Because of the significant radiation dose, which causes cataracts and thyroid cancer by the repeated and continuous radiation exposure, for the chest and the abdomen CT scans, it is required to use shielding devices to reduce radiation dose for examinations.

Evaluation of Ovary Dose for woman of Childbearing age Woman with Breast cancer in tomotherapy (가임기 여성의 유방암 토모치료 시 난소선량 평가비교)

  • Lee, Soo Hyeung;Park, Soo Yeun;Choi, Ji Min;Park, Ju Young;Kim, Jong Suk
    • The Journal of Korean Society for Radiation Therapy
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    • v.26 no.2
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    • pp.337-343
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    • 2014
  • Purpose : The aim of this study is to evaluate unwanted scattered dose to ovary by scattering and leakage generated from treatment fields of Tomotherapy for childbearing woman with breast cancer. Materials and Methods : The radiation treatments plans for left breast cancer were established using Tomotherapy planning system (Tomotherapy, Inc, USA). They were generated by using helical and direct Tomotherapy methods for comparison. The CT images for the planning were scanned with 2.5 mm slice thickness using anthropomorphic phantom (Alderson-Rando phantom, The Phantom Laboratory, USA). The measurement points for the ovary dose were determined at the points laterally 30 cm apart from mid-point of treatment field of the pelvis. The measurements were repeated five times and averaged using glass dosimeters (1.5 mm diameter and 12 mm of length) equipped with low-energy correction filter. The measures dose values were also converted to Organ Equivalent Dose (OED) by the linear exponential dose-response model. Results : Scattered doses of ovary which were measured based on two methods of Tomo helical and Tomo direct showed average of $64.94{\pm}0.84mGy$ and $37.64{\pm}1.20mGy$ in left ovary part and average of $64.38{\pm}1.85mGy$ and $32.96{\pm}1.11mGy$ in right ovary part. This showed when executing Tomotherapy, measured scattered dose of Tomo Helical method which has relatively greater monitor units (MUs) and longer irradiation time are approximately 1.8 times higher than Tomo direct method. Conclusion : Scattered dose of left and right ovary of childbearing women is lower than ICRP recommended does which is not seriously worried level against the infertility and secondary cancer occurrence. However, as breast cancer occurrence ages become younger in the future and radiation therapy using high-precision image guidance equipment like Tomotherapy is developed, clinical follow-up studies about the ovary dose of childbearing women patients would be more required.

Guideline for Imaging Dose on Image-Guided Radiation Therapy (영상유도방사선치료에 있어 영상선량 가이드라인)

  • Cho, Byung Chul;Huh, Hyun Do;Kim, Jin Sung;Choi, Jin Ho;Kim, Seong Hoon;Cho, Kwang Hwan;Cho, Sam Ju;Min, Chul Kee;Shin, Dong Oh;Lee, Sang Hoon;Park, Dong Wook;Kim, Kum Bae;Choi, Sang Hyoun;Kim, Hye Young;Ahn, Woo-Sang;Kim, Tae Hyeong;Han, Su Cheol
    • Progress in Medical Physics
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    • v.24 no.1
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    • pp.1-24
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    • 2013
  • As image-guided radiation therapy (IGRT) has been commonly used for more accurate patient setup and monitoring tumor movement during radiation therapy, the necessity for management of imaging dose is increased. However, it has not been an interest issue to radiation therapy communities because the imaging dose is much lower than the therapeutic dose. However, since the cumulative dose from 4DCT and repeated imaging for daily setup verificationin would not be ignorable, appropriate dose management based on ALARA (As Low As Reasonably Achievable) principle is required. In this study, we aimed that (1) survey on imaging equipments and modalities used for IGRT, (2) estimation of IGRT imaging dose depending on treatment types and equipments, (3) collecting data of effective dose on treatment sites from each equipment and imaging protocol, and thus finally provide guideline for imaging dose reduction and optimization.